Lateral canal pump

ABSTRACT

A lateral canal pump in which an open screw wheel operates within an open lateral canal with grooved walls having grooves running in a rotary direction so as to influence a circular parallel flow.

United States Patent 1191 Hagemann Apr. 16, 1974 41 LATERAL CANAL PUMP 2,282,569 5/1942 Fabig 415/53 T 2,696,789 121954 F b' [75] Invenm wali" Human", meme/Holst 2,814,434 11/1957 111,5. 415/211 7 Germany 3,280,752 10/1966 Luhmann 415/213 T [73] Assignee:v Silii G.m.b-H. & Co. KG, 7

A meme/Holst Germany FOREIGN PATENTS OR APPLICATIONS 621,691 4/1949 Great Britain 415/53 T [22] 281 1972 636,394 10/1936 Germany 415/53 T [21] Appl. ,No.: 248,549

Primary Examiner-C. J. Husar [30] Foreign Application Priority Data Apr. 30, 1971 Germany 2121280 57 ABSTRACT [52] US. Cl 415/53, 415/199, 415/213 1 [51] 11 11. Cl. F0411 5/00 A lateral canal pump i which an open screw wheel [58] new M Search 415/53 213 I99 operates within an open lateral canal with grooved 3 415/204 walls having grooves running in a rotary direction so 1 l as to influence a circular parallel flow.: [56] References Cited 7 I 1 UNITED STATES PATENTS 11 Claims, 16 Drawing Figures 1,640,591 8/1927 Borneman 415/213 T LATERAL CANAL PUMP This invention relates to a lateral canal pump in which an open screw wheel operates within an open lateral canal whose walls are grooved in a rotary direction so that a circular flow parallel to them is influenced.

A typical feature of lateral canal pumps is the fact that, at an output of zero, i.e., with a closed pressure plate, the operating level and the power requirement are at their highest. Under operating conditions, the operating level of the pump can many times not be checked so that its motor must be set at a general level which may be relatively high for a low flow. In addition, the pump normally works at low power for a high flow and operation at low flow'with closed pressure plates occurs only seldomly.

It is known that a lateral canals operational features can be altered with conducting ribs so that the operational power needs of the pump level off for low flow levels.

It has been shown that these ribs are difficult to produce. They have the further disadvantage of narrowing the cross-section of the lateral canal, so thata larger lateral canal cross-section is made necessary, bringing with it a higher power requirement.

An object of this invention is to provide a lateral canal pump with grooves along the interior structure of the canal that influence a circular flow and which are easier to produce and which require no additional power. a 1

Previously, it was thought necessary to influence this circular flow by means of protruding ribbed guiding surfaces. The present invention makes use of the fact that, with regard ,to influencing the desired flow, it is sufficient, and, concerning the production and power requirements it is moreover more advantageous, if in the present method, only the utmost range of circular flow be influenced by the grooved indentations.

The indentations preferably take the form of one or more grooves which suitably extend over the greater part of the internal circumference of the lateral canal, if necessary, even over the entire surface area. It is thereby not necessary to have a continuous unbroken indentation even though such a continuous indentation can in many cases beadvantageous. The circumferential surface canbedivided into many more suchindentations.

This effect isreinforced by placing two or more channel-like indentationsnext to each other (viewedin a radial direction) in the lateral canal. The effectcan frequently be further strengthenedwhen the channel-like indentations are sloped more .or less opposite the circumferential direction of thelateral canal.

Basically, the indentations can have any crosssectional formas long as at least one groove is present which issuitable for directing the circular flow along the walls of the lateral canal. In practice, a crosssection will preferably be chosen, which, as a casting modeLis found to take shapeingood order. This will very frequently become the grooveform.

Thearea of the groove cross-section should generally not be under about 3 percentof the area for the lateral canal cross-section, because cross-sections of under about 3 percent cause a sharp decrease in the desired effect. On the other hand, it is preferred that the area of the groove-cross-section not exceed 15 percentof the lateral canal area, because in this case as well, the

desired effect diminishes and the increase of the canal cross-section (lateral canal cross-section plus crosssection of groove) could lead to an increased power requirement. It is therefore optimal. that the area of the groove cross-section amount from 3 percent to about 15 percent of the area of the lateral canal cross-section. The same is valid for groove-like indentation crosssections.

It is still further advantageous, if the groove width, measured perpendicular to the direction of the groove, amounts to about one tenth toabout one third of the average cross-measurement of the lateral canal (height, width).

Finally, it is of further advantage if the edges of the indentations are left as sharp as possible. This is possible only to a limited degree in finishing the pump part of the lateral canal as a cast part. However, this principal effect caused by the sharpened edges, is nevertheless still sufficiently present during the inevitable slight rounding of the edges which is inevitable during finishing. The design of the indentation bed plays no part in this conducting effect.

It was found that the effect of the inventions lateral canal grooves is greatest when they are located in the part of the lateral canal wall opposite the rotor. However, this does not rule out that such indentations can also be placed in other arrangrnents on' the lateral canal. Since, in all probability, the effect of the indentations is in its conducting of the circular flow in the lateral canal, it is advantageous to place the indentations so that the flowinfluencing edges find themselves in the same cross-section range of the lateral canal in which the flow lines of the circular flow (corresponding to the hypothetical cross-section flow focus) are radially at their greatest concentration in the wall region. This is most often the case wherethe wall of the lateral canal approaches the hypothetical flow focus of the circular flow to the greatest degree. When, for example, the lateral canal is designed in a right angle-like crosssection, the indentations are preferably placed in the middle zone of the longer right angle side facing the rotor. 1 a

The objects and advantages of this invention can :be better understood with reference to the drawings whereinz i FIGS; 1 and 2 show a view of apressure-plate control disc as seen from the rotor side and an axial section of this control disc; i 1 i i y FIGS. 3-10 show corresponding illustrations of other embodiments in accordance with this invention;

FIGS. 13 and 14 show lateral canal cross-sections of two other embodiments of this invention;

FIGS. 15 and 16 are diagrams showingthe relationof operational level and power requirement to output in accordance with this invention.

With reference to the drawings there is shown the control disc regulator of the lateralcanal which consists of an inner hub (1),an outer flange (.2), which, with the corresponding flanges of the adjacent housing fits tightly, and a part of the wall (3), located between them which forms the lateral canal (4) and the current cross-section (5). The pressure opening (6) is located also in this part of the wall which marks the end of the lateral canal.

As shown in FIGS. 1 through 12, the lateral canal is located actually to the side of the screwxwheel. In addition, among all these embodiments a round rather than an oval cross-section is chosen for the lateral canal. In fact, it is an especial advantage of the invention that the lateral canal is actually located to the side of the screw wheel and/or that it has a cross-sectional form that is suitable for the hypothetical circular flow. Other crosssectional forms of the lateral canal, especially those in which the lateral canal is found partially outside the radial reach of the screw wheel, and in which the crosssectional form of the lateral canal has somewhat of a right-angle shape, should not be thereby excluded. Examples of such other forms which are within the scope of the invention are shown in FIGS. 13 and 14, where the lateral canal of FIG. 13 is in the form of a right angle, and the lateral canal of FIG. 14 lies with a certain portion of its cross-section surface outside the radial reach of the rotor.

In the embodiment shown in FIG. 1 the groove (3) forms at the beginning (7) of the lateral canal and continues unbroken to the pressure opening (6) where it ends. The groove (8) runs within the average reach of the part (4) of the lateral canal wall situated opposite the rotor. The groove (8) is actually a right angle crosssection. Its side walls form a right angle corner with the adjacent wall surfaces of the lateral canal. The groove bed at this corner could be rounded as well.

FIG. Sand FIG. 4 show a similar groove (9) which continues over the greater part of the lateral canal sur-' face. The distance between the beginning of the lateral canal(7) and the beginning of the groove (10) as well as between the end of the groove (11) and the end of the lateral canal (12) is about between 30 and 90. There is illustrated'further, in comparison with that of FIGS. 1 and2, a small displacement-of the groove radially outward. Yet'even in this case, it remains within the average reach of the part of the wall opposite the rotor.

In the embodiments of FIGS. and 6, most of the grooves running in the rotarydirection are arranged behind one. another in the-central part of the lateral canal wall opposite the lateral canal. The device of FIGS. 7 and 8 are similar to the above-described in that a majority of comparatively short groove sections are arranged behind one another in the lateral canal center opposite the rotor; however, in this case, the groove sections opposite the rotary direction are inclined, so that the incline of the first groove section in the rotary direction (13) is relatively large, amounting to about 90, while the incline of the last groove'section (14) in the rotary direction is slight, only about The incline of the groove sections lying between them is within these two figures and declines in the rotary direction. Varying from the illustrated form, the slopes of the combined groove sections are the same opposite the rotary direction.

As shown in FIGS. 9 and 10, the groove sections opposite the rotary direction can be inclined in the opposite direction, in which case, the incline is about the same.

According to FIGS. 11 and 12, two grooves (15) are placed beside one another along the greater length of the lateral canal. The effect is thereby enhanced.

It is clear from the drawings that the indentations may have many possible forms only in their use as grooves. Number, length, position and direction of the grooves are chosen from one case to the next according to the degree of desired effect, as well as for the desired power requirements.

Therefore the indentations need not lie absolutely and exclusively in the part of the lateral canal opposite the rotor, as is shown in FIG. 14, where, beside the groove (16) opposite the rotor, two additonal grooves (17) and (18) are located radially within and outside the part of the wall of the lateral canal respectively. Practically speaking, such arrangements are, for technical reasons, of little importance.

FIG. 13 shows a groove design in which both groove walls are of the same height, so that a step results which is situated against the direction of the circular flow which would be expected in this part of the wall.

FIGS. 15 and 16 illustrate the power characteristics obtainable with and without the inventions indentations; in both figures O-designated curves illustrate the typical operation without the inventions indentations, while the remaining curves coordinate the above design forms by the above noted figures and numbers.

It is obvious that the embodiments shown are only exemplary and a wide variety.

What is claimed is:

1. In a lateral canal pump having an open screw wheel in communication with an open lateral canal, the improvement which comprises means defining indentations in the walls of said lateral canal and forming edge surfaces in said walls in order to influence a circular flow in parallel directionto the rotary direction.

2. The-lateral canal pump of claim 1, wherein said indentations consist of at least one groove.

3. The lateral canal pump of claim 1, wherein said indentations extend over the greater part of the circumferential area of the lateral canal.

4. The lateral canal pump of claim 3, wherein said indentations extend over the combined periphery of the lateral canal.

5. The lateral canal pump of claim 1, wherein a plurality several indentations are distributed over the peripheral surface of the lateral canal. I

6. The lateral canal pump of claim S, wherein said indentations are radially arranged beside one another in the lateral canal.

7. The lateral canal pump of claim 2, wherein the cross-sectional surface of said groove amounts to about 3 to 15 percent of the cross-sectional surface of the lateral canal.

8. The lateral canal pumpof claim 7, wherein the width of said groove measured perpendicular to the groove direction amounts to from one tenth to one third of the average cross-dimension of the lateral canal.

9. The lateral canal pump of claim 1, wherein said indentations form sharp-edges with the walls of said lateral canal.

10. The lateral canal pump of claim 1, wherein said indentations in said open lateral canal are to the side of said screw wheel.

11. In a lateral canal pump having an open screw wheel operating in communication with a lateral canal located at the side of said screw wheel the improvement which comprises, means defining at least one groove in said canal and running in the rotary direction, the area of the groove cross-section being between about 3 percent and 15 percent of the lateral canal cross-section and the groove width measured perpendicular to the direction of the groove being about one tenth to one third the average cross measurement of the lateral canal, in order to influence a circular flow in a parallel direction to the rotary direction. 

1. In a lateral canal pump having an open screw wheel in communication with an open lateral canal, the improvement which comprises means defining indentations in the walls of said lateral canal and forming edge surfaces in said walls in order to influence a circular flow in parallel direction to the rotary direction.
 2. The lateral canal pump of claim 1, wherein said indentations consist of at least one groove.
 3. The lateral canal pump of claim 1, wherein said indentations extend over the greater part of the circumferential area of the lateral canal.
 4. The lateral canal pump of claim 3, wherein said indentations extend over the combined periphery of the lateral canal.
 5. The lateral canal pump of claim 1, wherein a plurality several indentations are distributed over the peripheral surface of the lateral canal.
 6. The lateral canal pump of claim 5, wherein said indentations are radially arranged beside one another in the lateral canal.
 7. The lateral canal pump of claim 2, wherein the cross-sectional surface of said groove amounts to about 3 to 15 percent of the cross-sectional surface of the lateral canal.
 8. The lateral canal pump of claim 7, wherein the width of said groove measured perpendicular to the groove direction amounts to from one tenth to one third of the average cross-dimension of the lateral canal.
 9. The lateral canal pump of claim 1, wherein said indentations form sharp-edges with the walls of said lateral canal.
 10. The lateral canal pump of claim 1, wherein said indentations in said open lateral canal are to the side of said screw wheel.
 11. In a lateral canal pump having an open screw wheel operating in communication with a lateral canal located at the side of said screw wheel the improvement which comprises, means defining at least one groove in said canal and running in the rotary direction, the area of the groove cross-section being between about 3 percent and 15 percent of the lateral canal cross-section and the groove width measured perpendicular to the direction of the groove being about one tenth to one third the average cross measurement of the lateral canal, in order to influence a circular flow in a parallel direction to the rotary direction. 